Post-hole digger



R. C. FRASER.

POST HOLEDIGGER.

APPLICATION men ocT. I5. 1918.

1,305,792. Patented June 3, 1919.

ii'nirnn s rarns PATENT curios.

RICHARD CLAYTON FRASER, OF CENTRAL CITY, COLORADO, ASSIGNOR OF ONE-THIRDTO WILLIAM R. FRASER, OF DURANGO, COLORADO.

POST-HOLE means. 7

ieosgiee.

To all whom it may concern:

Be it known that I, RICHARD O. FRASER, a citizen of the United States,residing at Central City, in the county of Gilpin and State of Colorado,have invented certain new and useful Improvements in Post-Hole Diggers,and I do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to earth boring tools and more particularly totools in the nature ofpost hole diggers. 7

'It is one of the objects of the present, invention to provide forimprovements in post hole diggers which will render instruments of thistype'more easily operable and more rapidly driven and thus to increasethe general utility oftheimplement; Another object of the inventionis'to provide a device of the character which is simple in construction,substantial in its parts and inexpensive and durable.

With these and other objects in view as will be rendered manifest in thefollowing specification, the invention consists in the construction, thecombination, and in details and in organization of the parts as morefully hereinafter described, relative to the embodiment of the inventionillustrated in the accompanying drawings, in which,

Figure 1 is a perspective view looking toward the bottom end of theimplement, and

Fig. 2 is a vertical, through the implement.

The digger comprises a cylindrical shell of suitable dimension and kindand thickness of material being illustrated at 2 in the drawing, theupper end of the cylinder being open as at 3, while its lower end istermi nated in the form of a helical edge 4, the helix making onecomplete turn about a central rod 5 extending through the sleevelongitudinal section or shell 2. The upper end of the shell is shiftablyconnected to the center rod 5, preferably by means of a split gaspipe'6, the lower end of which is bifurcated or divided into a number ofprongs 7, which are riveted or otherwise fastened securely to theadjacent end of the shell as at 8. While the sleeve or pipe 6 isslidable on the rod 5, it is rotative by the rod by suitable meansSpecification of Letters Patent. Patented June 3, 1919 Application filedOctober 15, 1918. Serial No. 258,769.

herein shown as comprising a pin 5 engaging the walls ofthe split pipe.

The center rod 5 may be in the form of a plece of gas pipe or othertubing having at its lower end a tapering point 10 and at the upper endof the rod there is connected the threaded cross connection 11, intowhich may be inserted the handles or levers 12, which may be of ordinarypipe form thus permitting cheapness of construction.

An important feature of the present invention resides in the provisionof the cutting means, which means not only provides for the cutting ofthe earth but also which ex: tends upwardly into the interior of theshell or cylinder tube.- This cutting means comprises a helix of a'suitable number of turns and which is coordinate with the helical edge 4of the cylinder or casing 2, and to which the perimeter of the lowerportion of the helix is secured as by means of lugs 15, a suitablenumber of which are bent up from the edge of the helix 16, this latterbeing shown as riveted as at 17 to the central rod 5. The shell 2 has acutting edge 18 ex tending longitudinally thereof and of a lengthsubstantially equal to the pitch between adjacent edgesof the blades ofthe helix, the edge 18 and the radial edge 19 of the helix beingperpendicular to one another or in a common plane so that they co-act incutting operation. Adjacent to its radial edge the cutter is providedwith a lip 20 extendingdownwardly substantially parallel to the axis ofthe rod 5 the function of which is to make a circular cut duringoperation.

By extending the length of the helix up substantially into the shelltube it is found that the cutting operation by the device is renderedeasier and that the implement can be operated more rapidly than otherforms of post diggers.

What I claim is:

1. An earth boring tool comprising a cylindrical shell open at its topand having its lower edge forming a helix of one turn with a straightlongitudinal lip connecting the terminals of the helical edge andforming a vertical cutter of that part of the shell; a sleeve attachedto the upper end of the shell and coaxial therewith; a center rod onwhich the sleeve is slidable without rotation; and an integral,multiturn helical cutter attached to the lower end of the rod, the pitchof the helix being coordinate with that of the end of the shell so thatthe first turn forms a bottom for the shell while the upper portion ofthe helix projects well up into the shell to facilitate cutting andcarryin of soil; the helix having a leading radiacutting edge; and meansfor holding the bottom edge of the shell.

2. An earth boring tool comprising a cylindrical shell open at its topand having its lower edge forming a helix of one turn with a straightlongitudinal lip connecting the terminals of the helical edge andforming a vertical cutter of that part of the shell; a sleeve attachedto the upper end of the shell and coaxial therewith; a center rod onwhich the sleeve is slidable without rotation; and an integral,multi-turn helical cutter attached to the lower end of the rod, the rodhaving its lower end shaped to form a fishtail cutter the pitch of thehelix being coordinate with that of the end of .the shell so that thefirst turn forms a bottom for the shell while the upper portion of thehelix projects well up into the shell to facilitate cutting and carryingof soil; the helix having a leading radial cutting edge; and means forholding the bottom edge of the shell.

3. An earth boring tool comprising a cylindrical shell open at its topand having its lower edge forming a helix of one turn with a straightlongitudinal lip connecting the terminals of the helical edge andforming a vertical cutter of that part of the shell; a sleeve attachedto the upper end of the shell and coaxial therewith; a center rod onwhich the sleeve is slidable without rotation; and an integralmulti-turn helical cutter attached to the lOWer end of the rod, thepitch of the helix being coordinate with that of the end of the shell sothat the first turn forms a bottom for the shell while the upper portionof the helix projects well up into the shell to facilitate cutting andcarrying of soil; the helix having a leading radial cut ting edge; andmeans for holding the bottom edge of the shell, the advance'end of thehelical cutter having a down-turned circle cutting lip disposed adjacentto the cutting edge of the shell.

4. An earth boring tool comprising a cylindrical shell open at its topand having its lower edge forming a helix of one turn with a straightlongitudinal lip connecting the terminals of the helical edge andforming a vertical cutter of that part of the shell; a sleeve attachedto the upper end of the shell and coaxial therewith; a center rod onWhich the sleeve is slidable without rotation; and an integral,multi-turn helical cutter attached to the lower end of the rod, thepitch of the helix being cooordinate with that of the end of the shellso that the first turn forms a bottom for the shell while the upperportion of the helix projects well up into the shell to facilitatecutting and carrying of soil; the helix having a leading radial cuttingedge; and means for holding the bottom edge of the shell the sleevebeing longitudi nally split, and a pin in the shank to spline the partsfor sliding action.

In testimony whereof I afi'ix my signature.

RICHARD CLAYTON FRASER.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Ifatents, Washington, D. G.

